Therapeutic Potential of Heparin/Digoxin Encapsulated Polymeric Nanoparticles: Modulation of Arrhythmias and Neuroinflammation Using Low-Intensity Pulsed Ultrasound on in Vitro and in Vivo Efficacy

Ventricular arrhythmias (VAs) are abnormal heart rhythms that primarily occur due to sympathetic overactivity (SOV). SOV can occur from microglia-mediated neuroinflammation. To overcome this, the non-invasive approach of Low-intensity pulsed ultrasound (LIPUS) modulating arrhythmias and neuroinflammation remains unclear. In this study, Heparin, an anticoagulant, and digoxin, a cardiac glycoside, are co-delivered via poly(ԑ-caprolactone) polymeric nanoparticles (Hep/Dx@PCL-NPs) to improve therapeutic efficacy and reduce systemic side effects. In vitro biocompatibility of Hep/Dx@PCL-NPs retains the viability of cells and reduces the apoptosis rate in H9C2 myocardial cells. In an in vivo study, rats were randomly assigned to four groups: Control, Control + LIPUS, Hep/Dx@PCL-NPs, and Hep/Dx@PCL-NPs + LIPUS. Cardiac dysfunction was induced via coronary artery ligation surgery, and the vulnerability of VAs was assessed through electrophysiological studies. Heart rate variability (HRV) and left stellate ganglion (LSG) neural activity were utilized to assess sympathetic nerve activity. LIPUS significantly reduced fibrosis, dysfunction, and hypertrophy compared to the control group. Likewise, LIPUS therapy drastically lowered VA vulnerability and restored gap junction remodeling. The anti-arrhythmic effects of Hep/Dx@PCL-NPs + LIPUS decreased the P2 × 7/NLRP3 pathway, which in turn reduced microglial activation, neuroinflammation, SOV, and ventricular proinflammatory cytokine releases. This finding emphasizes the efficacy of Hep/Dx@PCL-NPs + LIPUS treatment in modulating antiarrhythmic effects.